Loom With Detachable Connection Between a Drive Means and the Warp Beam of a Loom

ABSTRACT

The invention relates to a loom ( 1 ) with a warp beam ( 2 ) and a drive means ( 3 ), in particular, a warp beam gear, whereby the warp beam ( 2 ) has a warp beam flange ( 2.2 ) and a detachable connection is provided between the warp beam flange ( 2.2 ) and the drive means ( 3 ), said drive means ( 3 ) being mounted in a drive-side frame wall ( 4 ) of the loom ( 1 ) and the warp beam ( 2 ), the warp beam flange ( 2.2 ) and the drive means ( 3 ) are arranged on a common rotational axis ( 5 ). The drive means ( 3 ) is connected to the warp beam flange ( 2.2 ) by means of screws and the frame wall ( 4 ) is provided with recesses such that the screws may be screwed through the recesses and drillings in the drive means ( 3 ) into the warp beam flange ( 2.2 ).

The invention relates to a loom with a warp beam and a drive means, particularly a warp beam gear wheel for it, whereby the warp beam has a warp beam flange and a detachable connection is provided between the warp beam flange and the drive means.

Such looms having spur gear or wave gear clutches are known. The clutches are disengaged mechanically or hydraulically. For example, solutions are known from EP 1 057 912 and DE 197 24 150 wherein the drive torque moment is transmitted through switchable spur geared clutches. A play free, continuous transmission of the high drive torque moment, when weaving with a high warp thread tension, is achieved by additional safety elements. Both solutions have the disadvantages of a costly construction and a complicated operation. As a result the time needed for a warp beam exchange is prolonged. Further, there is the danger of a damage to the machine and to the product due to an improper operation.

Known clutches with a wave gearing for coupling the warp beam shaft and the drive means have the disadvantage that the coupling does not function free of play. This leads to uncontrolled variations in the warp thread tension during operation and thus to an impairment of the fabric quality. Although this disadvantage has been overcome by the solution described in EP 0 666 345, by means of an additional tensioning element that tensions the wave gearings of the warp beam shaft and the warp beam gear wheel against each other, this solution has, however, the disadvantage of a costly construction. A further disadvantage results due to the axial displacement of the warp beam gear wheel relative to the driving pinion during each separation of the drive train. This displaceable connection between the driving pinion and the warp beam gear wheel requires a certain initial play in the meshing gearing and is additionally subject to a certain wear and tear. Stated differently, even with the solution according to EP 0 666 345 a lasting transmission free of play of the torque moment is not assured.

Furthermore, all constructions with spur gear or wave gear clutches require relatively much space. This fact is contrary to efforts for making the structural width of the loom as small as possible.

The present applicant has realized already a space saving solution for looms by screwing the drive means, for example in the form of a gear wheel, directly to the warp beam shaft or to the warp beam tube and to remove the gear wheel with the warp beam from the loom with each warp beam exchange. This, however, makes the further transport of the warp beam more difficult. Further, there is the danger of damage to the gear teeth of the warp beam gear wheel during the transport and during the change of the warp beam gear wheel onto a new warp beam. The change of the warp beam gear wheel form the old to the new warp beam presents, in addition to extra work efforts, also a danger of injury to the worker when handling the loose, heavy warp beam gear wheel.

Thus, it is the object of the invention to provide a loom of the type described, which has a compact and rugged construction, which assures a highly loadable, durable and free of play transmission of the torque moment onto the warp beam and which makes possible a simple exchange of the large and heavy warp beam. Furthermore, the invention shall prevent damages to persons and equipment that could be caused by operating errors while exchanging the warp beam.

This object is achieved by means of a loom having the characteristics of the claims 1 and 5. Suitable further developments are defined in the respective dependent claims.

Accordingly, the drive means, preferably a warp beam gear wheel, according to claims 1 and 5, is connectable with the warp beam by means of one or more screws, whereby the screws are operable through holes in the frame wall. The term “holes” in this context is intended to include for example bores and openings of any shape and size and lateral notches in the frame wall. The number and dimensions of the screws are so selected that a safe transmission free of play of the torque moment from the drive means to the warp beam flange is assured. The operating of the screws through the holes in the frame wall makes possible a very close positioning of the drive means to the frame wall and thus a compact construction. On the one hand the compact method of construction saves construction space, while, on the other hand it increases the stability of the drive. Particularly in connection with high speed looms the tendency to vibrate is thereby advantageously minimized. The screw tightening and screw loosening of the warp beam can be performed from the outer side of the frame wall, which is substantially simpler and safer than an operation on the inner side. The drive means is mounted in a frame wall positioned on the drive side. The warp beam can also be mounted through the drive means on its driven side in the frame wall as long as it is screw connected with the drive means. The described close arrangement is an advantage for a stable, long life mounting of the drive means in the frame wall, because due to the close axial spacing between the drive means and the mounting position, the forces to be taken up by the bearing are also relatively small, particularly when the drive means is unscrewed from the warp beam.

According to the present invention, when using a gear wheel as drive means, the meshing of the gear wheels exists unchanged also during a warp beam exchange. This feature permits close gear teeth tolerances and the gear teeth are subject to a small wear and tear. In turn, this feature also assures in this point a durable torque moment transmission substantially free of play. During the production no costly manufacturing measures are necessary, which would permit an axial displacement of the gear wheels relative to each other, while however minimizing play in the circumferential direction.

In the embodiment with one screw, that screw is received in an eccentrically arranged bore in the drive means, whereby the warp beam flange is centered and fixed in the common axis of rotation with at least one further element that is operatively connected with the warp beam flange and with the drive means. This element is for example a fitting hub or a fitting pin.

In order to make a warp beam exchange simple, in a preferred embodiment of the invention, a support is arranged on the side of the warp beam at the drive means. The support rotates with the drive means. The support can for example be constructed as a pair of support bearings on which the warp beam supports itself during installation as well as during removal as long as it is not connected to the drive means. This intermediate support makes easier, above all, during installation of the warp beam, the alignment of the threaded holes in the warp beam flange, with the holes in the drive means and thereafter the screwing-in of the screws. In spite of the large weight of the warp beam the latter can be rotated on rotatable support bearings with just a low energy consumption. Thus, an additional intermediate support structure for example in the form of a separate support frame, is no longer required.

Markings are advantageously provided on the drive means and on the drive facing side of the frame wall for a simple and safe operational sequence of the warp beam exchange. These markings indicate to the operator when the mentioned support assumes a warp beam holding position. In connection with support roller bearings this would be, for example, a lower position in which the warp beam rests on the support rollers. These markings may be visually seen or they may be electronic markings, for example, which are sensed by sensors that are connected, in a signal transmitting manner, with the loom control. The sensors signal to the loom control when the drive means stands in a position suitable for an installation of the warp beam or for removal of the warp beam. The control can generate for an operator a respective display for example on a display panel. A visible marking is advantageously so secured to the loom that it is clearly recognizable from different positions, when the drive means is in a position suitable for installing and for removing of the warp beam.

In order to further secure the warp beam exchange against operating errors, it is provided by a further advantageous embodiment that the connection can be released and bolted only in one angular position, suitable for the warp beam exchange, of the drive element which is arranged about the common rotational axis. The suitable angular position is in turn predetermined by the arrangement of the support.

A preferred possibility of this securing can be achieved by a hole pattern with an asymmetric arrangement of the through holes in the drive means, a respective arrangement of the holes in the frame wall and by a small spacing between the drive means and the frame wall. If the holes in the frame wall are for example through holes having a diameter insignificantly larger than that of the screw heads and if these through holes are arranged in the frame wall in accordance with the same hole pattern as the through holes in the drive means, then the screws can be screwed-in and -out only when the hole pattern in the drive means is in that angular position in which it is congruent with the hole pattern in the frame wall. In this angular position, the support stands in a warp beam holding position. It is understood that the asymmetric arrangement includes various kinds of asymmetries. For example, these are arrangements in which all the holes have the same spacing from the central axis but are arranged with different angles relative to each other. Alternatively, these are holes which are arranged with different spacings from the central axis while having the same angular spacing from each other. Alternatively, these are holes which are arranged with different spacings from the central rotational axis and with different angles from each other.

In the embodiment of the invention with but one screw, which is arranged eccentrically, the described securing is advantageously realized in that the screwing-in and the screwing-out of the screw through the frame wall and through the closely spaced and arranged drive means, into and out of the warp beam flange is preferably possible only when the hole in the drive element s positioned exactly opposite to a respectively shaped hole in the frame wall.

A further preferred embodiment of the invention provides that more threaded holes are provided in the warp beam flange than holes arranged in the drive means. By a respective arrangement of the threaded holes in the warp beam flange and thus the warp beam can be installed in several angular positions relative to the common rotational axis even if the holes in the drive means are arranged asymmetrically. Thus, less rotating of the new, heavy warp beam into a suitable angular position is required. The same facilitation can be achieved according to the invention with one eccentrically arranged hole in the drive means and with several threaded holes in the warp beam flange.

One or more screws are preferably constructed as dowel screws for centering the warp beam relative to the common rotational axis.

Possible damages due to operating errors during a warp beam exchange in a loom of the described type are avoided by a further advantageous embodiment of the invention. According to this embodiment the head of the at least one screw is smaller than the hole in the frame wall. The drive means with the screws is arranged so close to the frame wall that each screw not screwed-in reaches necessarily with its head into the hole of the frame wall. In order to make sure that each not screwed-in screw reaches far enough into the respective hole, for definitely preventing a further rotation movement of the drive means, an energy storing means is operatively connected to and arranged with each screw, particularly a compression spring. The compression spring pushes the screw in a direction opposite to its screw-in direction into the holes of the frame wall. For this purpose the compression spring bears against a shoulder on the inner surface of the hole in the drive means. However, in order to prevent that the not screwed-in screw is pushed completely out of the hole in the drive means, the screw is secured by a securing element, for example a securing ring. The securing element cooperates with a limit stop provided on the drive means, for example in the form of a fitting bushing arranged on the inner circumference of the respective hole in the drive means. The securing element holds the at least one screw in a predetermined end position. In this way each not screwed-in screw is pressed against the limit stop by the energy storing means and held in this predetermined position.

Each screw is so dimensioned that it withstands the torque moment of a driving motor. That means, that a not screwed-in screw blocks the drive of the warp beam in that the screw bears against the inside of the respective hole in the frame wall. Preferably, a switch-off protector provided at the motor switches the motor off when blocking occurs. In this way damages to the loom and to the product are avoided. Such damages could otherwise occur during operation with not screwed-in screws and a warp beam only partially secured.

The invention and further resulting advantages are explained in more detail in the following with reference to an example embodiment.

In the attached drawings:

FIG. 1 shows a side view of the driven side of the warp beam;

FIG. 2 shows a view of the driven side of the warp beam with the drive elements;

FIG. 3 shows a sectional view of the drive elements of the warp beam according to section plane C-C in FIG. 1; and

FIG. 4 shows an enlargement of a detail D in FIG. 3.

FIG. 1 shows a side view of the driven side of the warp beam 2 with four screws 6 and four holes 4.1 in the frame wall 4. A loom 1 of the type described is provided with a warp beam 2 and a motor 7 for driving the warp beam. The holes 4.1 and the screws 6 are arranged in accordance with an asymmetric hole pattern. The heads of the screws 6 in the drive means 3 are visible through the holes 4.1 in the frame wall 4. In the shown angular position of the drive means 3 all screws 6 can be screwed-in and screwed out. This is not possible in any other angular position of the drive means 3, because in that case not all or no screws 6 at all can be inserted and withdrawn through the holes 4.1 in the frame wall 4.

According to FIG. 2 the warp beam 2 comprises substantially a warp beam tube 2.1, a warp beam flange 2.2 and warp beam discs 2.3 arranged on the warp beam tube. The warp beam discs serve as lateral limits for the warp threads not shown. FIG. 2 shows only the warp beam disk 2.3 on the driven side of the warp beam. The warp beam flange 2.2 can be constructed as a one piece construction with the warp beam tube 2.1 or it can be a separately produced element rigidly connected to the warp beam tube. Separately produced warp beam flanges 2.2 make it possible to use differently formed warp beam tubes 2.1 whereby a warp beam flange 2.2 is adapted to the respective warp beam tube and can itself be used advantageously as an adapter element.

FIG. 2 further shows a motor 7 rigidly secured to a drive side frame wall 4. The motor drives a motor pinion not shown for driving a drive means 3 constructed as a gear wheel. The drive means 3 is bolted to the warp beam flange 2.2. The warp beam flange 2.2 is, in turn, rigidly secured to the warp beam tube 2.1.

The embodiment of FIG. 2 is equipped with a support 8 in the form of support bearings which are laterally secured to the drive means 3. In this view only one of two support bearings is visible. The second support bearing is secured to the drive means 3 behind the visible support bearing and with the same spacing to the rotational axis 5. The two support bearings form together a rest for the warp beam flange 2.2. The support 8 holds the warp beam 2 in an installation position and in a removal position, however, while the warp beam is not bolted to the drive means 3. The temporary supporting of the warp beam 2 on support bearings 8 is, above all, advantageous during the installation of the warp beam 2 because the warp beam 2 can thus be rotated with a little energy input about its rotational axis into an angular position suitable for screwing-in the screws 6.

FIG. 3 shows the assembled parts of the warp beam drive in a sectional view along the section plane C-C in FIG. 1. The drive means 3 is connected to the warp beam flange 2.2 by screws 6. In this embodiment the warp beam flange 2.2 is a separately produced element which is rigidly connected to the warp beam tube 2.1. The drive means 3, the warp beam flange 2.2 and the warp beam tube 2.1 are thereby arranged around the common rotational axis 5. FIG. 3 also shows the closely spaced, space saving arrangement of the warp beam flange 2.2, of the drive means 3 and of the frame wall 4 to one another. This arrangement is made possible first of all by the holes 4.1 in the frame wall for screwing-in and screwing-out the screws 6.

FIG. 4 shows in an enlarged portion one of the screw connections between the drive means 3 and the warp beam flange 2.2. The screws 6 are operable through the holes 4.1 in the frame wall 4 and through the holes 3.1 in the drive means 3 for screwing into the warp beam flange 2.2. Thus, the warp beam 2 can be rigidly connected with the drive means 3 and separated from the drive means 3.

In the shown embodiment each screw 6 is operatively connected to the drive means 3 by a compression spring 9 arranged on the circumference of the screw shaft. The compression spring 9 bears against a shoulder 3.3 on the inner surface of the hole 3.1 and displaces the not screwed-in screw 6 opposite to the screw-in direction. Thus, the compression spring pushes the screw further into the hole 4.1 of the frame wall 4. The screw 6 is secured by a securing ring 10 so that the compression spring 9 cannot push the screw 6 completely out of the hole 3.1 of the drive means 3. The securing ring 10 is arranged at the shaft circumference of the screw 6 and limits the displacement distance of the screw 6 by bearing against a fitting bushing 11 forming a stop. The bushing 11 is pressed into the hole 3.1 of the drive means 3. This arrangement of the securing ring 10 and of the fitting bushing 11 also prevents that a screw 6 which is not screwed-in can fall out, for example due to vibrations. 

1-14. (canceled)
 15. A loom comprising an exchangeable warp beam (2), a frame wall (4), a drive means (3) mounted to said frame wall in axial alignment with a rotational axis (5) of said warp beam (2), said warp beam comprising a warp beam flange (2.2) facing said frame wall and said drive means, a separable screw connection between said warp beam flange and said drive means, said separable screw connection comprising at least one threaded hole (2.4) in said warp beam flange, at least one first through hole (3.1) in said drive means (3) and at least one screw for engaging said at least one threaded hole (2.4) through said at least one first through hole (3.1), said frame wall comprising at least one second through hole (4.1) so that said at least one screw can pass through said at least one second through hole (4.1) and through said at least one first through hole (3.1), wherein said at least one screw is operable on a frame wall side facing away from said drive means for engaging and disengaging said at least one threaded hole (2.4) in said warp beam flange when said at least one first through hole, said at least one second through hole and said at least one threaded hole are axially aligned with each other.
 16. The loom of claim 15, wherein said separable screw connection comprises a first plurality of threaded holes (2.4) in said warp beam flange, a second plurality of through holes (3.1) in said drive means (3), a third plurality of through holes (4.1) in said frame wall (4) and a number of screws threaded for cooperation with any one of said first plurality of threaded holes in said warp beam flange, and wherein said screws are dimensioned for passing through any one of said first and second pluralities of through holes.
 17. The loom of claim 15, further comprising a support (8) for said warp beam (2), and markings positioned on said drive means (3) and on said frame wall (4) for indicating when said support (8) is in a warp beam holding position, wherein said support (8) has warp beam supporting elements rotatable with said drive means (3) and wherein said support (8) is arranged at said drive means (3) on a warp beam facing side.
 18. The loom of claim 16, further comprising a support (8) for said warp beam (2), and wherein said at least one screw (6) and said number of screws (6) can be screwed into said threaded hole or holes in said warp beam flange only when said support (8) is in a warp beam holding position, wherein said support (8) has warp beam supporting elements rotatable with said drive means (3), and wherein said support is arranged at said drive means (3) on a warp beam facing side.
 19. The loom of claim 16, wherein said through holes (3.1) of said second plurality of through holes (3.1) are arranged in accordance with an asymmetric hole pattern, wherein said through holes of said third plurality of through holes (4.1) are also arranged in accordance with said asymmetric hole pattern, and wherein said drive means (3) is positioned so close to said frame wall (4) that said at least one screw and said number of screws can pass through respective through holes of said second and third plurality of through holes only when said respective through holes of said second and third pluralities of through holes are in an axial alignment with one another and with said threaded hole or holes, said loom further comprising a warp beam support (8) in a warp beam holding position for said threaded screws to pass through said respective through holes of said second and third plurality of through holes for engagement with and disengagement from said threaded hole or holes.
 20. The loom of claim 15, wherein said at least one screw (6) can pass through said at least one first through hole and through said at least one second through hole when said first and second through holes are in axial alignment with one another, said loom further comprising a warp beam support in a warp beam holding position for said at least one screw to pass through said first and second through holes.
 21. The loom of claim 16, wherein said first plurality of threaded holes (2.4) comprises such a number of threaded holes, that said warp beam flange (2.2) can assume any one of a plurality of angular positions relative to said drive means and relative to a common axis (5) of rotation, said warp beam flange (2.2) being connectable to said drive means (3) by said separable screw connection in any one of said plurality of angular positions.
 22. The loom of claim 15, wherein said at least one screw is constructed as a dowel or fitting screw.
 23. The loom of claim 15, wherein said at least one second through hole (4.1) in said frame wall (4) is so dimensioned that said at least one screw, as it passes through said at least one second through hole, is operable in said at least one second through hole, wherein a spacing between the drive means and the frame wall is short enough so that said at least one screw can reach into said at least one second through hole (4.1) in response to a biasing force pushing said at least one screw (6) into said at least one second through hole (4.1) in a direction opposite a screw-in direction when said at least one screw is still disengaged from said at least one threaded hole in said warp beam flange so that a rotational motion of said drive means (3) exceeding a predetermined rotational angle is blocked by said at least one screw reaching into said at least one second through hole (4.1).
 24. The loom of claim 23, comprising a screw biasing energy storing device for applying said biasing force to said at least one screw.
 25. The loom of claim 24, wherein said energy storing device is a compression spring.
 26. The loom of claim 24, further comprising a securing element (10) arranged on said at least one screw, a limit stop (11) arranged on said drive means (3) said securing element and said limit stop cooperating in limiting a displacement of said at least one screw in a direction opposite to a screw-in direction to a predetermined end position.
 27. The loom of claim 26, further comprising a drive motor (7) for driving said drive means (3), and wherein any one of said screw or screws is dimensioned to withstand a torque moment applied by said drive motor (7).
 28. The loom of claim 27, further comprising a switch off protector operatively connected to said drive motor (7) for switching off said drive motor when a blocking occurs. 